4-Methoxyphenol is produced from p-benzoquinone and methanol via a free radical reaction.[  Mequinol is a common active ingredient in topical drugs used for skin depigmentation. As a topical drug mequinol is often mixed with tretinoin, a topical retinoid. A common formulation for this drug is an ethanolic solution of 2% mequinol and 0.01% tretinoin by mass.Dermatologists commonly prescribe the drug …